1. Field of the Invention
The present invention relates to apparatuses and methods for identifying personnel and, more particularly, to apparatuses and methods for identifying personnel based on visual characteristics of the irises of their eyes.
2. Description of the Related Art
Iris recognition, or “iris capture” is a method of biometric personal identification that uses pattern recognition algorithms based on images of at least one of the irises of an individual's eyes. Iris recognition uses camera technology to produce images of the details of the iris. These images are converted into digital templates and provide mathematical representations of the iris that are used to identify individuals.
Due to hardware limitations, the images that are captured are often blurred. However, iris image deblurring can greatly improve the robustness for less intrusive iris capture systems. Most known iris deblurring algorithms ignore the characteristics of the capture system itself, and focus only on features that are directly computed from the iris images. More particularly, in many iris capture systems, system delay is often seen between the identified capturing event and the real shutter release of the camera. The delay may consist of several parts, the time to drive the lens to the desired position, the time to release the shutter and capture the image, and the time to drive the pan-tilt unit. Therefore, if a user is moving, the focused depth of the camera and the actual depth of the eyes are usually different. When the depth difference is larger than the depth of the field (DOF) of the camera, the defocus blur occurs, which can greatly deteriorate the performance of the iris recognition.
What is neither disclosed nor suggested in the art is a method of iris image deblurring that is able to compensate for focusing characteristics of the camera in cases in which it is not practical to achieve an ideal focus position of the lens before the image is captured.